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@d3noob
Last active November 30, 2020 07:10
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Simple vertical tree diagram using v4
license: mit

This is a simple vertical tree diagram written with d3.js v4.

This is designed to be used as a starting point for further development as part of documenting an update to the book D3 Tips and Tricks to version 4 of d3.js.

<!DOCTYPE html>
<meta charset="utf-8">
<style> /* set the CSS */
.node circle {
fill: #fff;
stroke: steelblue;
stroke-width: 3px;
}
.node text { font: 12px sans-serif; }
.node--internal text {
text-shadow: 0 1px 0 #fff, 0 -1px 0 #fff, 1px 0 0 #fff, -1px 0 0 #fff;
}
.link {
fill: none;
stroke: #ccc;
stroke-width: 2px;
}
</style>
<body>
<!-- load the d3.js library -->
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
var treeData =
{
"name": "Top Level",
"children": [
{
"name": "Level 2: A",
"children": [
{ "name": "Son of A" },
{ "name": "Daughter of A" }
]
},
{ "name": "Level 2: B" }
]
};
// set the dimensions and margins of the diagram
var margin = {top: 40, right: 90, bottom: 50, left: 90},
width = 660 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
// declares a tree layout and assigns the size
var treemap = d3.tree()
.size([width, height]);
// assigns the data to a hierarchy using parent-child relationships
var nodes = d3.hierarchy(treeData);
// maps the node data to the tree layout
nodes = treemap(nodes);
// append the svg obgect to the body of the page
// appends a 'group' element to 'svg'
// moves the 'group' element to the top left margin
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom),
g = svg.append("g")
.attr("transform",
"translate(" + margin.left + "," + margin.top + ")");
// adds the links between the nodes
var link = g.selectAll(".link")
.data( nodes.descendants().slice(1))
.enter().append("path")
.attr("class", "link")
.attr("d", function(d) {
return "M" + d.x + "," + d.y
+ "C" + d.x + "," + (d.y + d.parent.y) / 2
+ " " + d.parent.x + "," + (d.y + d.parent.y) / 2
+ " " + d.parent.x + "," + d.parent.y;
});
// adds each node as a group
var node = g.selectAll(".node")
.data(nodes.descendants())
.enter().append("g")
.attr("class", function(d) {
return "node" +
(d.children ? " node--internal" : " node--leaf"); })
.attr("transform", function(d) {
return "translate(" + d.x + "," + d.y + ")"; });
// adds the circle to the node
node.append("circle")
.attr("r", 10);
// adds the text to the node
node.append("text")
.attr("dy", ".35em")
.attr("y", function(d) { return d.children ? -20 : 20; })
.style("text-anchor", "middle")
.text(function(d) { return d.data.name; });
</script>
</body>
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